drivers/regulator/of_regulator.c

   1 /*
   2  * OF helpers for regulator framework
   3  *
   4  * Copyright (C) 2011 Texas Instruments, Inc.
   5  * Rajendra Nayak <rnayak@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/of.h>
  16 #include <linux/regulator/machine.h>
  17 #include <linux/regulator/driver.h>
  18 #include <linux/regulator/of_regulator.h>
  19
  20 #include "internal.h"
  21
  22 static const char *const regulator_states[PM_SUSPEND_MAX + 1] = {
  23         [PM_SUSPEND_MEM]        = "regulator-state-mem",
  24         [PM_SUSPEND_MAX]        = "regulator-state-disk",
  25 };
  26
  27 static void of_get_regulation_constraints(struct device_node *np,
  28                                         struct regulator_init_data **init_data,
  29                                         const struct regulator_desc *desc)
  30 {
  31         struct regulation_constraints *constraints = &(*init_data)->constraints;
  32         struct regulator_state *suspend_state;
  33         struct device_node *suspend_np;
  34         unsigned int mode;
  35         int ret, i;
  36         u32 pval;
  37
  38         constraints->name = of_get_property(np, "regulator-name", NULL);
  39
  40         if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
  41                 constraints->min_uV = pval;
  42
  43         if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
  44                 constraints->max_uV = pval;
  45
  46         /* Voltage change possible? */
  47         if (constraints->min_uV != constraints->max_uV)
  48                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  49
  50         /* Do we have a voltage range, if so try to apply it? */
  51         if (constraints->min_uV && constraints->max_uV)
  52                 constraints->apply_uV = true;
  53
  54         if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
  55                 constraints->uV_offset = pval;
  56         if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
  57                 constraints->min_uA = pval;
  58         if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
  59                 constraints->max_uA = pval;
  60
  61         if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
  62                                   &pval))
  63                 constraints->ilim_uA = pval;
  64
  65         /* Current change possible? */
  66         if (constraints->min_uA != constraints->max_uA)
  67                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  68
  69         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
  70         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
  71         if (!constraints->always_on) /* status change should be possible. */
  72                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  73
  74         constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");
  75
  76         if (of_property_read_bool(np, "regulator-allow-bypass"))
  77                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  78
  79         if (of_property_read_bool(np, "regulator-allow-set-load"))
  80                 constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
  81
  82         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
  83         if (!ret) {
  84                 if (pval)
  85                         constraints->ramp_delay = pval;
  86                 else
  87                         constraints->ramp_disable = true;
  88         }
  89
  90         ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
  91         if (!ret)
  92                 constraints->settling_time = pval;
  93
  94         ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
  95         if (!ret)
  96                 constraints->settling_time_up = pval;
  97         if (constraints->settling_time_up && constraints->settling_time) {
  98                 pr_warn("%s: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
  99                         np->name);
 100                 constraints->settling_time_up = 0;
 101         }
 102
 103         ret = of_property_read_u32(np, "regulator-settling-time-down-us",
 104                                    &pval);
 105         if (!ret)
 106                 constraints->settling_time_down = pval;
 107         if (constraints->settling_time_down && constraints->settling_time) {
 108                 pr_warn("%s: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
 109                         np->name);
 110                 constraints->settling_time_down = 0;
 111         }
 112
 113         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
 114         if (!ret)
 115                 constraints->enable_time = pval;
 116
 117         constraints->soft_start = of_property_read_bool(np,
 118                                         "regulator-soft-start");
 119         ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
 120         if (!ret) {
 121                 constraints->active_discharge =
 122                                 (pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
 123                                         REGULATOR_ACTIVE_DISCHARGE_DISABLE;
 124         }
 125
 126         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
 127                 if (desc && desc->of_map_mode) {
 128                         mode = desc->of_map_mode(pval);
 129                         if (mode == REGULATOR_MODE_INVALID)
 130                                 pr_err("%s: invalid mode %u\n", np->name, pval);
 131                         else
 132                                 constraints->initial_mode = mode;
 133                 } else {
 134                         pr_warn("%s: mapping for mode %d not defined\n",
 135                                 np->name, pval);
 136                 }
 137         }
 138
 139         if (!of_property_read_u32(np, "regulator-system-load", &pval))
 140                 constraints->system_load = pval;
 141
 142         constraints->over_current_protection = of_property_read_bool(np,
 143                                         "regulator-over-current-protection");
 144
 145         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 146                 switch (i) {
 147                 case PM_SUSPEND_MEM:
 148                         suspend_state = &constraints->state_mem;
 149                         break;
 150                 case PM_SUSPEND_MAX:
 151                         suspend_state = &constraints->state_disk;
 152                         break;
 153                 case PM_SUSPEND_ON:
 154                 case PM_SUSPEND_TO_IDLE:
 155                 case PM_SUSPEND_STANDBY:
 156                 default:
 157                         continue;
 158                 }
 159
 160                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 161                 if (!suspend_np)
 162                         continue;
 163                 if (!suspend_state) {
 164                         of_node_put(suspend_np);
 165                         continue;
 166                 }
 167
 168                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 169                                           &pval)) {
 170                         if (desc && desc->of_map_mode) {
 171                                 mode = desc->of_map_mode(pval);
 172                                 if (mode == REGULATOR_MODE_INVALID)
 173                                         pr_err("%s: invalid mode %u\n",
 174                                                np->name, pval);
 175                                 else
 176                                         suspend_state->mode = mode;
 177                         } else {
 178                                 pr_warn("%s: mapping for mode %d not defined\n",
 179                                         np->name, pval);
 180                         }
 181                 }
 182
 183                 if (of_property_read_bool(suspend_np,
 184                                         "regulator-on-in-suspend"))
 185                         suspend_state->enabled = true;
 186                 else if (of_property_read_bool(suspend_np,
 187                                         "regulator-off-in-suspend"))
 188                         suspend_state->disabled = true;
 189
 190                 if (!of_property_read_u32(suspend_np,
 191                                         "regulator-suspend-microvolt", &pval))
 192                         suspend_state->uV = pval;
 193
 194                 if (i == PM_SUSPEND_MEM)
 195                         constraints->initial_state = PM_SUSPEND_MEM;
 196
 197                 of_node_put(suspend_np);
 198                 suspend_state = NULL;
 199                 suspend_np = NULL;
 200         }
 201 }
 202
 203 /**
 204  * of_get_regulator_init_data - extract regulator_init_data structure info
 205  * @dev: device requesting for regulator_init_data
 206  * @node: regulator device node
 207  * @desc: regulator description
 208  *
 209  * Populates regulator_init_data structure by extracting data from device
 210  * tree node, returns a pointer to the populated struture or NULL if memory
 211  * alloc fails.
 212  */
 213 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 214                                           struct device_node *node,
 215                                           const struct regulator_desc *desc)
 216 {
 217         struct regulator_init_data *init_data;
 218
 219         if (!node)
 220                 return NULL;
 221
 222         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 223         if (!init_data)
 224                 return NULL; /* Out of memory? */
 225
 226         of_get_regulation_constraints(node, &init_data, desc);
 227         return init_data;
 228 }
 229 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 230
 231 struct devm_of_regulator_matches {
 232         struct of_regulator_match *matches;
 233         unsigned int num_matches;
 234 };
 235
 236 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 237 {
 238         struct devm_of_regulator_matches *devm_matches = res;
 239         int i;
 240
 241         for (i = 0; i < devm_matches->num_matches; i++)
 242                 of_node_put(devm_matches->matches[i].of_node);
 243 }
 244
 245 /**
 246  * of_regulator_match - extract multiple regulator init data from device tree.
 247  * @dev: device requesting the data
 248  * @node: parent device node of the regulators
 249  * @matches: match table for the regulators
 250  * @num_matches: number of entries in match table
 251  *
 252  * This function uses a match table specified by the regulator driver to
 253  * parse regulator init data from the device tree. @node is expected to
 254  * contain a set of child nodes, each providing the init data for one
 255  * regulator. The data parsed from a child node will be matched to a regulator
 256  * based on either the deprecated property regulator-compatible if present,
 257  * or otherwise the child node's name. Note that the match table is modified
 258  * in place and an additional of_node reference is taken for each matched
 259  * regulator.
 260  *
 261  * Returns the number of matches found or a negative error code on failure.
 262  */
 263 int of_regulator_match(struct device *dev, struct device_node *node,
 264                        struct of_regulator_match *matches,
 265                        unsigned int num_matches)
 266 {
 267         unsigned int count = 0;
 268         unsigned int i;
 269         const char *name;
 270         struct device_node *child;
 271         struct devm_of_regulator_matches *devm_matches;
 272
 273         if (!dev || !node)
 274                 return -EINVAL;
 275
 276         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 277                                     sizeof(struct devm_of_regulator_matches),
 278                                     GFP_KERNEL);
 279         if (!devm_matches)
 280                 return -ENOMEM;
 281
 282         devm_matches->matches = matches;
 283         devm_matches->num_matches = num_matches;
 284
 285         devres_add(dev, devm_matches);
 286
 287         for (i = 0; i < num_matches; i++) {
 288                 struct of_regulator_match *match = &matches[i];
 289                 match->init_data = NULL;
 290                 match->of_node = NULL;
 291         }
 292
 293         for_each_child_of_node(node, child) {
 294                 name = of_get_property(child,
 295                                         "regulator-compatible", NULL);
 296                 if (!name)
 297                         name = child->name;
 298                 for (i = 0; i < num_matches; i++) {
 299                         struct of_regulator_match *match = &matches[i];
 300                         if (match->of_node)
 301                                 continue;
 302
 303                         if (strcmp(match->name, name))
 304                                 continue;
 305
 306                         match->init_data =
 307                                 of_get_regulator_init_data(dev, child,
 308                                                            match->desc);
 309                         if (!match->init_data) {
 310                                 dev_err(dev,
 311                                         "failed to parse DT for regulator %s\n",
 312                                         child->name);
 313                                 of_node_put(child);
 314                                 return -EINVAL;
 315                         }
 316                         match->of_node = of_node_get(child);
 317                         count++;
 318                         break;
 319                 }
 320         }
 321
 322         return count;
 323 }
 324 EXPORT_SYMBOL_GPL(of_regulator_match);
 325
 326 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 327                                             const struct regulator_desc *desc,
 328                                             struct regulator_config *config,
 329                                             struct device_node **node)
 330 {
 331         struct device_node *search, *child;
 332         struct regulator_init_data *init_data = NULL;
 333         const char *name;
 334
 335         if (!dev->of_node || !desc->of_match)
 336                 return NULL;
 337
 338         if (desc->regulators_node)
 339                 search = of_get_child_by_name(dev->of_node,
 340                                               desc->regulators_node);
 341         else
 342                 search = of_node_get(dev->of_node);
 343
 344         if (!search) {
 345                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 346                         desc->regulators_node);
 347                 return NULL;
 348         }
 349
 350         for_each_available_child_of_node(search, child) {
 351                 name = of_get_property(child, "regulator-compatible", NULL);
 352                 if (!name)
 353                         name = child->name;
 354
 355                 if (strcmp(desc->of_match, name))
 356                         continue;
 357
 358                 init_data = of_get_regulator_init_data(dev, child, desc);
 359                 if (!init_data) {
 360                         dev_err(dev,
 361                                 "failed to parse DT for regulator %s\n",
 362                                 child->name);
 363                         break;
 364                 }
 365
 366                 if (desc->of_parse_cb) {
 367                         if (desc->of_parse_cb(child, desc, config)) {
 368                                 dev_err(dev,
 369                                         "driver callback failed to parse DT for regulator %s\n",
 370                                         child->name);
 371                                 init_data = NULL;
 372                                 break;
 373                         }
 374                 }
 375
 376                 of_node_get(child);
 377                 *node = child;
 378                 break;
 379         }
 380
 381         of_node_put(search);
 382
 383         return init_data;
 384 }